Exfoliation of kaolinite by urea-intercalation precursor and microwave irradiation assistance process

摘要

A type of exfoliated kaolinite was produced by urea-intercalation and original microwave irradiation assisted method. The product was investigated by Fourier trans-formation infrared (FT-IR) spectroscopy, X-ray diffraction(XRD), scanning electronic microscopy (SEM), Brunauer-Emmett-Teller (BET) and laser particle analysis techniques.FT-IR spectra show that NHCO molecule exists in the intercalated kaolinite. XRD analyses indicate that the kao-linite sheet-like structure was disordered after microwave irradiation. The urea decomposition process and explosion effect between the sheet-like structures of kaolinite under microwave irradiation were discussed. The SEM and BET analyses reveal that the end product is exfoliated kaolinite with thin particles and increased surface area. Size and zeta potential analyses show that the particle size distribution is between 250 nm and 550 nm with normal distribution and the particle is negatively charged. In comparison with the conventional grind method, the process adopted appears to be economic and the exfoliated kaolinite end product may display a significantly enhanced performance in industrial applications.